<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            font-size: 50;
            /* 提示css属性：单词的首字母 */
        }
    </style>
</head>
<body>
    <div></div>
    <!-- 生成div带类名的 -->
    <div class="obx"></div>

    <ul>
        <li>111</li>
        <li>111</li>
        <li>111</li>
    </ul>
</body>
</html>